1. Field of the Invention
This invention relates to a non-woven fabric produced according to a hot-melt adhesion process and having a superior bulkiness and strength.
2 Description of the Related Art
Heretofore, as processes for producing non-woven fabrics using hot-melt adhesive fibers, heated roll process, hot-air-blowing process, etc. have been known, and non-woven fabrics having a basis weight of 15 to 200 g/m.sup.2 have been used in the fields of surface materials for disposable diaper interlining fabrics, disposable clothes, etc.
However, non-woven fabrics produced by conventional processes have been in the form of a thin and flat sheet, deficient in bulkiness and also insufficient in strength. In order to improve the strength of non-woven fabrics, if the temperature and pressure at the time of heat treatment are raised, the non-woven fabrics become thinner and stiffer so that the bulkiness is lost. Processes for improving the strength of non-wove fabrics by incorporating reinforcing fibers thereinto are disclosed in Japanese patent application laid-open No. Sho 61-41357/1986 or Japanese patent application laid-open No Sho 62-215057/1987, but even according to these processes, it is impossible to improve the bulkiness of non-woven fabrics.
As a process for imparting the bulkiness to non-woven fabrics having a low basis weight, there has been known a process of providing crepe-like lateral wrinkles on non-woven fabrics by peeling off non-woven fabrics from a drum by employing a doctor knife in the suction drum dryer process. However, non-woven fabrics obtained according to this process, the bulkiness is improved, but the fabrics have such drawbacks that they are easily elongated by slight tension in the longitudinal direction and liable to be deformed.